"Be flush with money" is an idiom that means to be wealthy or to have more money than one needs. There are various synonyms that can be used instead of this phrase, such as "to have deep pockets," "to be rolling in dough," "to be loaded," "to be a millionaire," "to be filthy rich," "to be a tycoon," "to be a magnate," or "to be well-off." All these expressions convey the idea of excess wealth and financial success. However, it is important to note that being rich is not always a guarantee of happiness or fulfillment. Money can bring comfort and opportunities, but it does not necessarily lead to happiness or prosperity.